As a network with the largest coverage at present, the power line network has a huge potential utilization value; in addition, owing to the fact that the power network requires data transmission functions such as controlling signal transmission and dispatching automation data transmission, etc., power network communication techniques take an important role. As the electric power industry is developed and the informatization level of the electric power is improved continuously, there is an increasingly obvious trend of interpenetration between power network and power information network. Utilizing existing power transmission lines to implement data communication not only involves a very low cost, but also is simple in network construction and maintenance.
Early in the 1920s, data transmission through power lines began to draw people's attention. Later, this technology was developed quickly, along the continuous development and maturing of power line communication techniques, this technology has been widely applied in different power line networks, including high-voltage, medium-voltage, and low-voltage power line networks, etc. For example, power carrier communication technique utilizes power lines for data transmission. However, conventional power line communication techniques require special devices to manipulate data signals, including modulation, filtering, and demodulation, etc, these special devices not only cause increased cost, but also bring failure risks.
Since high-power semiconductor switching devices were developed, power electronic techniques have been developed and improved rapidly, and power electronic convertor circuits have been widely applied in electric power systems increasingly. Especially, since the 1980s, as semiconductor device manufacturing techniques were developed, the power processing capacities and switching speeds of switching devices have been improved remarkably, and power electronic devices have been applied more and more widely, almost involving all electric power application domains, ranging from electric power generation, electric power storage, electric power transmission, to electric power utilization. Power electronic devices applied in a power network are connected with power lines, and are mainly used to implement power transmission control. Utilizing power electronic devices to implement power transmission and data transmission through power lines at the same time not only can eliminate the demand for special communication devices and thereby save the cost, but also has wide application prospects under the situation of rapid development of power electronics power control techniques in power networks.